Critical Phenomena of Ether. 

 Table II. 



823 



v (normal vols.). 



t. 



t- 194-55. 



(V c ±y)XlOO 

 Vc. 



0-0170320 



467-504 



-0-046 



5-55 



•0172320 



467521 



- -029 



4-44 



•0174320 



467-535 



- 015 



3-33 



•0176320 



467542 



- -008 



2-22 



•0178320 



467547 



- -003 



111 



•0180320 (Vc) 



467-550 



•000 



o-oo 



•0182320 



467*552 



+ -002 



111 



•0184320 



467-556 



+ -006 



2-22 



•0186320 



467-563 



+ -013 



3-33 



•0188320 



467574 



+ -024 



444 



critical volume through the temperature C + o, 15. The con- 

 stants a and b, as well as the theoretical critical volume V c , 

 are derived from the critical data given by Young (20) 

 (0 C = 194-4; P c =35'61 atmospheres), and are a = 0*0347314, 

 6 = 0-00601066, V c = 0-0180320. The temperatures (t) were 

 then calculated for the volumes given in the table from the 

 formula 



t=(p + ±)("-bW 



where p = 



R(273 + 194-55) a 



(Vc-b) 



v.»- 



From the table it appears that a difference of temperature 

 of 0°'014 C. between the two portions of the substance may 

 produce a difference of density of about 4*5 per cent. Owing 

 to the great pressure under which the changes of density 

 occur and the small temperature slope through the glass walls 

 of the tube, it may be expected that the establishment of 

 equilibrium will be a slow process. 



Tube XIV. was raised to a temperature of about 0°*13 C. 

 above 6 C ; the time which elapsed before the opalescence 

 became absolutely uniform in appearance was 14 minutes. 

 This does not seem an unduly long period for the establish- 

 ment of equilibrium and seems to render a liquidogenic 

 hypothesis superfluous. 



It must be acknowledged that the slight differences of 

 temperature occurring in the thermostat would tend to acce- 

 lerate the establishment of equilibrium, both by increasing 

 the rate of transmission of heat through the walls of the tube 

 and by producing convection currents, though the latter were 

 not perceptible. Some quantitative knowledge of the relation 



